A known torque fluctuation absorber is provided, for example, on a drivetrain between an engine and a transmission. The known torque fluctuation absorber absorbs (restrains) torque fluctuations generated between the engine and the transmission. The known torque fluctuation absorber includes a damper portion that absorbs (restrains) the torque fluctuations by means of a spring force, a hysteresis portion that absorbs (restrains) the torque fluctuations by means of a hysteresis torque due to friction, and a limiter portion that generates slippage when torsion generated between a rotational shaft of the engine and a rotational shaft (an input shaft) of the transmission may not be absorbed by the damper portion and the hysteresis portion.
A known torque fluctuation absorber is disclosed in JP2010-230162A (which will be hereinafter referred to as Reference 1). In a limiter portion of the torque fluctuation absorber of Reference 1, a lining plate is arranged via first and second friction members between a cover plate and a pressure plate. The first friction member is slidably pressed against the cover plate and the lining plate and the second friction member is slidably pressed against the pressure plate and the lining plate (i.e., both surfaces of the first friction member, which face toward an engine and a transmission, respectively, are slidably pressed against the cover plate and the lining plate and both surfaces of the second friction member, which face toward the engine and the transmission, respectively, are slidably pressed against the pressure plate and the lining plate). According to such configuration of the limiter portion, the first friction member and the second friction member may move radially. Therefore, the first friction member and the second friction member are formed into annular shapes. Additionally, guide portions for restricting the first friction member and the second friction member from moving radially are arranged at the cover plate and the pressure plate (see FIG. 1 of Reference 1) or are arranged at the lining plate (see FIG. 2 of Reference 1).
According to the torque fluctuation absorber of Reference 1, the guide portions for restricting the first friction member and the second friction member from moving radially are arranged only at radially outward sides of the first friction member and the second friction member. Therefore, for example, the first friction member may move radially inwardly beyond or within an area sandwiched between the lining plate and the cover plate, or the second friction member may move radially inwardly beyond or within an area sandwiched between the lining plate and the pressure plate. In such case, characteristics of the limiter portion of the torque fluctuation absorber may vary.
A need thus exists for a torque fluctuation absorber which is not susceptible to the drawback mentioned above.